Robert Hammond Patrick, Jr. (born November 5, 1958) is an American actor. He is well known for his work in the science fiction genre, and is a Saturn Award winner.

Patrick dropped out of college when drama class sparked his interest in acting, receiving his first professional acting job in the 1986 television film Eye of the Eagle. He went on to appear in supporting roles in such films as Die Hard 2, Terminator 2: Judgment Day (as the T-1000), Wayne's World, Last Action Hero, Fire in the Sky, Cop Land, The Faculty, Walk the Line, We Are Marshall, Bridge to Terabithia, Spy Kids, and Flags of Our Fathers. He also starred in such television shows as The Sopranos, The Outer Limits, Elvis, The Unit, The X-Files (as FBI Special Agent John Doggett), Last Resort and From Dusk Till Dawn: The Series.

Patrick is described as someone who has "developed a solid reputation within the industry", with critics, fans, and co-stars alike praising his "work ethic, personality, and consistent performances".